Cognitive Symptoms in Schizophrenia Recognizing and Treating Cognitive Deficits in Schizophrenia

"Cognition” has more than one meaning. Cognitive-behavioral therapy refers to therapies that work on changing automatic thoughts and resulting schemas. When effective, cognitive therapy helps patients:

• Become aware of automatic thoughts

• Appreciate how these lead to schemas that distort global perception and limit one’s repertoire of responses

• Question and alter thoughts and schemas and thus achieve cognitive restructuring

A common metaphor for successful cognitive-behavioral therapy is that a patient comes in seeing the glass as “half empty” and leaves able to see that even “half-empty” glasses are simultaneously “half-full.”

In contrast, cognitive remediation, developed by neuropsychologists who initially used techniques for helping persons with traumatic brain injury, uses exercises-many computer-based-and other techniques to help patients with deficits in underlying processes that lead to disruptions in thinking. Cognitive remediation is focused not on distortions in global schemas but on neurocognitive processes that need to be either strengthened or bypassed by auxiliary pathways.

Pharmacotherapy for cognitive symptoms uses medications to correct dysfunctions in the processes that underlie thinking. Eventually, we will find ways to combine cognitive remediation with pharmacological interventions in treating cognitive symptoms in schizophrenia and other neuropsychiatric disorders.

An excellent operational definition for cognition as conceptualized in this article is that of Medalia and Revheim,¹ 2 leaders in the field of cognitive remediation. “Cognition refers to thinking skills, the intellectual skills that allow you to perceive, acquire, understand and respond to information. This includes the abilities to pay attention, remember, process information, solve problems, organize and reorganize information, communicate and act on information.”^1(p5)

During the 1970s and 1980s, empirical work led researchers to propose that schizophrenia be seen as a disorder comprising more than one underlying process.^2-4 In the 1990s, as pharmaceutical companies began marketing atypical antipsychotics as agents that improved negative as well as positive symptoms in addition to having fewer motor adverse effects, the concept of schizophrenia as a multidimensional disorder became widely accepted.⁵

Assessing cognition

Large-scale pharmaceutical company studies, along with investigator-initiated studies they inspired, frequently used 1 or more of the following symptom severity rating scales:

• The Scale for the Assessment of Negative Symptoms (SANS)⁶

• The Scale for the Assessment of Positive Symptoms (SAPS)⁷

• The Positive and Negative Syndrome Scale (PANSS)⁸

Large-scale studies provided data for SANS/SAPS and the PANSS-rated symptoms, which led to the approval of risperidone, olanzapine, quetiapine, ziprasidone, and aripiprazole and allowed for factor analysis.

Factor analysis of the SANS/SAPS ratings revealed 3 factors: positive, negative, and disorganized symptoms. Factor analysis of the PANSS-rated symptoms revealed 5 factors: positive, negative, dysphoric mood, excitement/hostility (sometimes called activation), and cognitive (sometimes called autistic preoccupation) symptoms. For both SANS and SAPS, poor performance on neuropsychological tests was found to correlate with the negative and disorganized factors. Negative symptoms were related to poor performance on tests of verbal learning and memory, verbal fluency, visual memory, and visual-motor sequencing, while disorganized symptoms were correlated with lower verbal IQ and poor concept attainment.⁹

For the PANSS, poor performance on neuropsychological tests was found to correlate with the negative and the cognitive/autistic preoccupation factors, but not with severity of positive symptoms. In a study by Opler and colleagues,¹⁰ PANSS negative symptoms were found to be associated with difficulties in performing the Wisconsin Card Sorting Test (WCST), a measure of executive functioning and prefrontal integrity. Bell and colleagues¹¹ found that the PANSS cognitive factor significantly correlated with poorer performance on all neuropsychological tests in a comprehensive battery that included the WCST.

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